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111.
An UDPG: cyanidin 3-O-glucosyltransferase was isolated and purified about 260-fold from the flower buds ofSenecio x hybridus. The enzyme showed a pH optimum of 7.5 and no additional cofactors were required. The Km values for cyanidin and UDPG were
0.33 and 0.20 mM, respectively. Its molecular mass estimated by Sephacryl S-200 chromatography was 52 kDa. 相似文献
112.
B. A. Bergmann W. P. Hackett H. Pellett 《In vitro cellular & developmental biology. Plant》1996,32(3):161-164
Summary Somatic embryogenesis was observed with explants taken from four types ofAesculus tissue: (a) shoots of 4-wk-oldin vitro germinated excised embryos (seed fromA.×arnoldiana), (b) roots of 4-wk-oldin vitro germinated excised embryos (seed fromA.×arnoldiana), (c) shoots from newly forced 3-yr-old seedlings (A. glabra), and (d) newly forced shoots from a 30-yr-old tree (A.×arnoldiana “Autumn Splendor”). Shoots provided three types of explants, single node, shoot apex, and internodal section, and all exhibited
embryogenesis.
Proembryogenic masses developed in a few cases after 6 wk in culture but were more commonly seen after 3 mo. The yellow, friable
proembryogenic masses emerged from proximal cut ends of explants. Almost all cultures that formed embryos possessed leaves,
either from developing apical or axillary buds or from adventitious buds, prior to the emergence of proembryogenic masses.
Only tissues that had begun to senesce and had been exposed to cytokinin (benzyladenine at 5 or 25 μM) formed somatic embryos. Embryos with distinct cotyledonlike structures and root/shoot axes developed during the 10 to 16
wk following the inital emergence of proembryogenic masses. Enhanced frequency of embryogenesis was obtained by dark culture
of root and shoot explants from 4-wk-old germinated embryos (A.×arnoldiana) and by dark and cold (5°C) treatment of shoot tissue cultures derived from 3-yr-old seedlings (A. glabra). Embryogenic potential was greatest in the most juvenile tissue and least in the mature tissue. Five percent of shoot explants
taken from the 30-yr-old select treeA.×arnoldiana “Autumn Splendor” produced somatic embryos. 相似文献
113.
Masayuki Yamamoto Norio Hayashi Goro Kikuchi 《Biochemical and biophysical research communications》1983,115(1):225-231
Synthesis of δ-aminolevulinate synthase in a rabbit reticulocyte lysate system directed by total polysomes from the liver of allylisopropylacetamide-treated rats was studied with the combined use of [3H]leucine and a specific rabbit antibody. The protein synthesis observed in the cell-free system employed represented mainly the peptide chain elongation and its termination rather than the net synthesis involving initiation. Synthesis of δ-aminolevulinate synthase in this cell-free system was inhibited progressively with the increased addition of hemin; the synthesis was reduced to about 40% by about 30 μM hemin. Synthesis of total protein, however, was not significantly affected by the addition of hemin. The data obtained suggest that heme inhibits a peptide chain elongation step in the synthesis of δ-aminolevulinate synthase. 相似文献
114.
Substance P stimulated the uptake of guanidinium in neuroblastoma X glioma hybrid cells and neuroblastoma cells but not in polyploid glioma cells. Guanidinium has previously been shown to pass the action potential Na+ channel in the two neuronal cell lines. Half-maximal stimulation was reached at 3 microM substance P and, with the hybrid cells, a saturation was seen above 10 microM. The analogue (D-Pro2,D-Trp7,9)-substance P, recently described as a substance P antagonist, caused a stimulation of guanidinium uptake comparable to that seen in the presence of substance P and did not inhibit the stimulation exerted by substance P. The pharmacological properties of the substance P-activated ion channel were investigated. Tubocurarine, phentolamine and propranolol blocked the substance P-stimulated guanidinium uptake with half-maximal inhibitory concentrations of 0.5, 5 and 50 microM. A similar characteristics has been found previously with the veratridine-activated Na+ channel in the cell lines investigated here. Peptides structurally related to substance P such as physalaemin and eledoisin, or others such as neurotensin, bradykinin, D-Ala2, Met5-enkephalinamide and ACTH(1-24) did not affect guanidinium uptake. In view of the high concentrations of substance P required for eliciting an effect in the cell lines, the involvement of specific receptors is questioned. A direct interaction of the peptide with the action potential Na+ channel is discussed. 相似文献
115.
Fusarium oxysporum f. sp. pisi and F. solani f. sp. cucurbitae degrade the isoflavone biochanin A (I) along the sequence: ldihydrobiochanin A3-(p-methoxyphenyl)-4,6-diketo-5,6-dihydro-4H-pyran 3,4-dihydroxyphenylacetic acid. F. oxysporum f. sp. apii, F. moniliforme, F. aquaeductum and F. solani f. sp. phaseoli first O-demethylate I to genistein, whichisdegraded to dihydrogenistein 3-(p-hydroxyphenyl)-4,6-diketo-5,6-dihydro-4H-pyran 3,4-dihydroxyphenylacetic acid. The significance of these alternative homologous catabolic routes are discussed.Abbreviations TLC
Thin layer chromatography
- NMR
Nuclear magnetic resonance
- HPLC
High performance liquid chromatography
- UV
ultraviolet
Dedicated to Prof. Dr. Karl Schneider, Münster, at the occasion of his 70th birthday 相似文献
116.
The number of copies of viral DNA in DNA of cells transformed by adenovirus type 2 has been determined by following the kinetics of reassociation of 32P-labeled viral DNA in the presence of unlabeled DNA extracted from transformed and control cells. There is close to one copy of adenovirus 2 DNA for every diploid quantity of cell DNA. 相似文献
117.
Harman and norharman, known as comutagens of many chemicals, were tested for their effect on the binding to DNA of 3-amino-1-methyl-5H-pyrido(4,3-b)indole, (Trp-P-2), a potent mutagen found with harman and norharman in the pyrolysate of tryptophan (1). We demonstrated that the alteration of the DNA helix by intercalation of these comutagens to DNA does not affect the affinity of this potent mutagen for DNA. Covalent binding, however, was inhibited by the comutagens. 相似文献
118.
Paclitaxel and 10-deacetylbaccatin III (10-DAB III) were produced in suspension cultures of Taxus × media var. Hicksii grown in shake-flasks and in a 7-l bioreactor reaching, in the bioreactor, 4.4 mg l−1 (on day 14) and 37.5 mg l−1 (on day 11). In shake-flasks the highest total content of paclitaxel and 10-DAB III was 7.3 mg l−1 (on day 4) and 8.8 mg l−1 (on day 18). Phenylalanine, at 0.05 mM, increased paclitaxel accumulation in cells cultivated in bioreactor and flasks 30-fold and 9-fold (from 0.02 mg l−1 to 0.6 mg l−1 and to 0.2 mg l−1, respectively). The 10-DAB III content in cells from flasks was increased from 0.4 mg l−1 to 1.6 mg l−1. 相似文献
119.
W. E. Van de Weg 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(8):1092-1096
Phytophthora fragariae var. fragariae is the causal agent of red stele (red core) root rot in strawberry (Fragaria spp.). The inheritance of resistance to one isolate of this fungus was studied in 12 segregating populations of F.×ananassa derived from crosses between four resistant cultivars (‘Climax’, ‘Redgauntlet’, ‘Siletz’, and ‘Sparkle’) and three susceptible
cultivars (‘Blakemore’, ‘Glasa’, and ‘Senga’ Sengana’). The analysis clearly supports the hypothesis of a single segregating
dominant resistance gene. It is proposed that this gene be designated Rpf2.
Received 12 November 1996 / Accepted: 22 November 1996 相似文献
120.
By means of dropping GA3(50 ppm) and NAA (40 ppm) on the hybrid boll-embryo culturein vitro, one F1 plant ofG. hirsutum × G. bickii was obtained; when F1 branches were grafted on upland cotton and then back-crossed with upland cotton under short-day and cooler-night condition,
some BC1 seeds could be harvested. The characteristic segregation was very violent in early generation. Through 3 times of back-crossing
and selecting, ten stable hybrid lines with the character of both male parent (viz. red petal-purple spot and strong fibre)
and female parent (plant type, earliness, white fibre, lint length, etc.) were established. These lines were assigned as HB
red flower lines (HBRL). Transference of character ofG. bickii to upland cotton was proved to be successful for the first time. These new germplasms may play an important role in both
the genetic research and new cotton variety breeding. 相似文献